This disclosure relates to ceramic compacts of phosphor compositions, particularly phosphors for use in lighting applications and methods for making such ceramic compacts.
Some white light-emitting devices comprise a blue LED combined with yellow phosphor such as YAG:Ce, TAG:Ce, or Silicate etc. For backlighting of LCD display purpose, in order to obtain a display with high color reproducibility, a bright red phosphor can be helpful to compensate for the red deficiency in the white light generated by these conventional phosphor systems. For lighting purpose, a red phosphor is can also help to produce warm white light with high color rendering index. But a good red phosphor is difficult to obtain because an increasing Stokes shift can lead to a low quantum yield. Phosphor powders such as K2SiF6:Mn4+ and K2TiF6:Mn4+ are red emitters, but they tend to be unstable.